A sixth person has died in the Upper East Side Legionnaires’ outbreak, which has sickened 90 people since it was first identified in early July, according to the city health department. The outbreak of the severe form of pneumonia hospitalized more than 70 people, six of whom remain in the hospital, according to the city health department. The city health department says the outbreak is likely linked to a water-cooling tower on the Upper East Side that was contaminated with Legionella bacteria, which can cause Legionnaires' disease when inhaled. But city health officials say it will take more testing to determine which tower is actually responsible for the outbreak. Despite city laws requiring the proper maintenance of cooling towers to prevent the growth of Legionella, this is Manhattan's second deadly outbreak of Legionnaires’ disease in two years.